International best seller David Baldacci pens the stunning conclusion to Cahills vs. Vespers! David Baldacci is the author of 23 books for adults, each of which has become both a national and international best seller.

Amy and Dan have managed to rescue one of the Cahills kidnapped by the Vespers, but the remaining hostages are still in peril. Their search for the next ransom item leads Amy and Dan to Turkey and then to Italy where a visit to the site of an ancient disaster changes everything. The Vespers are far more dangerous than the siblings ever imagined and, even worse, it looks like they have an undercover mole posing as a Cahill. Amy and Dan have to face the biggest decision of their lives with nowhere to turn... and no one to trust.

After pulling some spectacular heists, Amy and Dan have become two of Interpol's most wanted criminals. So when Vesper One orders them to steal the world's largest diamond, they know they're facing life in prison...or worse. But with the Cahill hostages still in peril, Amy and Dan have no choice but to launch a mission that leads them to an ancient city full of dangerous secrets. With a Vesper mole sabotaging the Madrigals from inside, Amy and Dan have to fulfill their enemy's request before it's too late. Vesper One has developed a taste for killing Cahills, and Amy and Dan aren't going to wait to see who's next.

The Vespers have ordered Amy and Dan to find a legendary map that belonged to Marco Polo, and the hunt takes them to Eastern Europe where they make a terrifying discovery about one of their supposed “allies.”

Amy and Dan find themselves in a new global race but this time, everything’s different. Those closest to them might be working for the enemy, and Amy and Dan are forced to ask themselves how far they’re willing to go to save the kidnapped Cahills. How much can you risk when there’s no one to trust?